
Description
Anhydrite is one of those strange mineral species which occurs commonly, in evaporite beds, but just hardly ever in crystals. Naica, at Mun. de SaucilloIt in Mexico is one of the few places, along with one or two in Germany, where crystals are known, and these Mexican crystals are very different to the blocky, colourless glassy ones from the German evaporite occurrences. This crystal is quite bold, reaching 8 cm in length and showing a very faint pale blue colour. Its bladed form is quite distinctive and has a thin partial coating of Calcite microcrystals on three sides - the front face clear, and displaying a fine silky lustre to the Anhydrite and vertical growth lines. This is a significant crystal for this species. It is from the superb systematic collection assembled by the brothers Martin and Michael Günther (1951-2007 & 1956-2021) in Germany.